A cooling device for the gun barrels of firearms in accordance with the preamble is known from German Letters Patent DE-PS 31 45 764, which is particularly suited for automatic firearms and heavy-duty automatic cannons. In connection with such heavy-duty firearms firing highly developed munitions, the great wear of the gun barrels is a result of the fact that the surface heat cannot be dissipated with sufficient speed. The heat stress, which occurs in rapid sequence when firing a volley, causes surface tensions and changes in the material. In addition, because of the outflowing powder gases, as well as the friction between the shell and the gun barrel, the material of the gun barrel is worn off.
To extend the service life of the gun barrels, the above mentioned patent proposes to provide cooling conduits in the area of the end section of the gun barrel adjoining a drum, which are oriented radially outward between the individual cartridge seats and which are connected with a main conduit for coolant supply extending in the drum axis. The cooling conduits are connected with nozzles which extend parallel in respect to the longitudinal direction of the drum, terminate in the front face of the drum and are arranged at the same distance from the longitudinal axis of the drum as the center longitudinal axis of the cartridge seats. Blocking elements for the nozzles are provided in the cooling conduits which, in the case of firing, briefly release the respective nozzle located in the area of the barrel opening. The blocking elements are, for example, slides, which can be displaced by means of control elements sliding along a control cam during the rotating movement of the drum. The coolant reaches the interior wall of the gun barrel directly through the nozzles. In this case the nozzles are only opened for the period of time they slide by the rear of the gun barrel, and coolant is only provided if firing takes place. However, the length of sliding time can be too short in connection with gun barrel systems of higher cyclic rates, or respectively with more intense rhythmic firing, so that not enough coolant reaches the gun barrel and insufficient cooling is possibly provided.